Ocean modifier foam spray?
We need dynamic particle emission to do real foam spray. The foam mask in the Ocean Sim modifier was created to be ready once Blender caught up with that feature. 

Once Lukas's Particle Nodes project is finished, it should allow for us to do that. http://phonybone.planetblender.org

The foam mask would be the source of the dynamic particle generation. The nice thing about the ocean mesh generated is that there are speed vectors associated with the waves, which I believe should also be able to be sampled and applied to the dynamic particles' starting velocities. Fingers crossed!